Effects Of RAd-p53and CPT-11Combina-tion Apoptosis Of Colon Careinoma Cell Line HT-29

ObjectiveThe Present study was to observe the effects of rAd-p53，CPT-11aloneand combination on cell viability and apoptosis of colon carcinoma cell line HT-29，to investigate the synergistic effect of rAd-p53and CPT-11combination andto explore potential mechanisms of inducing apoptosis.MethodsRecombinant Human Ad-p53Injection，CPT-11alone and combination ofcell inhibition rate was measured by MTT method. The morphological changeswere observed with fluorescence microscope dyed in Acridine Orange andEthidium Bromide; Cell cycle phase distribution and Apoptosis were determinedby flow cytometry with PI and AV/PI. The protein expression of Livin wasmeasured by Western blot. The expression of Livin mRNA was determined byReal Time PCR.ResultsRecombinant Human Ad-p53Injection，CPT-11alone and combinationcould suppress the growth of human colon carcinoma HT-29cells in time-anddose-dependent manner in. When HT-29were treated with the combination,theeffect of synergistic inhibition on the growth was demonstrated in the higherconcentration. Cell cycle was arrested at the G2/M phase, and apoptosis of cellscould be efficiently induced by in group of Recombinant Human Ad-p53Injection and CPT-11combination.Western blot and Real Time PCR showed theexpression of Livin mRNA and Livin protein were efficiently down-regulated afterthe use of the two agents in combination.ConclusionsrAd-p53combining with CPT-11can definitely inhibit the growth ofcolorectal cancer cell line HT-29，also the inducing apoptosis action wasobserved．Its mechanism may be associated with the down-regulation of Livin.